Air-heating apparatus.



J. MD. ARNEIL. 7

AIR HEATING APPARATUS.

APPLICATION FILED SEPT. 5. 1917.

1 ,278,4 1 Q, I Patented Sept. 10, 1918.

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AlR HEATING APPARATUS.

APPLICATION FILED SEPT- 5.-- 1911.

PatentedSept. 10,1918.

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' AIR-HEATING APPARATUS.

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Specification of Lette'rs latent.

Patented se t; io, 1918.

Application filed September 5, 1917. Serial No. 189,890.

To all whom it may concern:

Be it known that 1, JAMES MGCORKINDALE ARNEIL, a subject of the King of the United Kingdom of Great Britain and Ireland, and residing at Paisley, Renfrewshire, Scotland, have invented a certain new and useful Tmprovement in Air-Heating Apparatus, of which the following is a specification.

This invention relates to improvements in airheating apparatus or so-called unit heaters of the type comprising a casing inclosing tubular elements supplied with hot water or steam, and fitted with a fan for causing a current of air to How in'contact with the exterior surface of such elements.

The invention contemplates the employment of heating elements of a simple type comprising preferably parallelly disposed sections, Whether of the form usually designated as radiators or of theform designated as pipe coils, and consists primarily in the novel disposition of the heating surfaces hereinafter described whereby improved results are obtained.

A secondary feature of the invention consists in the provision of a damper or damp ers for interrupting automatically communication between the fan and the casing when the fan runner is at rest, whereby the fan motor is protected from hot air currents,

and the apparatu allowed to operate by natural draft.

For the purpose of the following description, it is assumed for convenience that the air is propelled over the heating surfaces by the air inlet and surmounting the casing.

'The invention is illustrated by way of example in the accompanying drawings in which Figures 1 and 2 are vertical sections at right angles to one another.

In the construction shown, the radiators or pipe coils I are disposed in converging inclined banks of which the component sections of each bank occupy a horizontal position, the walls 2 of the casing parallel to the axes of said sections being inclined so as to converge in the opposite direction, and the walls 2 of the casing being vertical.

Preferably there are provided four such banks, comprising two outer banks and two inner banks, the banks converging downwardly so that, the inner banks inclose an inner wedge-shaped space 3 of V-section; the casing being of truncated pyramidal formso as to afiord between each of the outer banks and the adjacent wall 2 of the casing an outer wedge-shaped space approximately A-section.

The component sections of adjacent inner and outer banks are disposed in staggered relationship so that air flowing from the inner wedge-shaped space 3 to the outer wedge-shaped spaces 4: will make efl'ective contact with the heating) surfaces.

The fan 5 is prefera ly mounted on the top of the casing and centrally thereof, so as to force the air to be heated into the inner wedge-shaped space 3, from which it travels transversely between the sections into the outer wedge -shaped spaces 4, whenc it is discharged at the bottom of the appa atus, as shown by the. arrows.

With the arrangement described the resistance to the flow of air between the various sections is uniform, and the length of travel of the air from the fan 5 to the outlet is practicallv the same throughout the crosssection of the descending air column.

As each of the transversely directed streams of air flowing between the radiator sections meets the heating surfaces which form the lateral'boundaries of thatstream at the initial air temperature and leaves the same at the ultimate air temperature, maximum surface efficiency is insured; further, by reason that the paths for the air streams are, in effect, in parallel and not in series, the air is not superheated at any point, but, on the contrary, the entire volume of air discharged is practically at the same temperature.

It is understood that, if desired, a less or greater number of banks may be employed and that the supply of heating medium to the inner or the outer banks may be out off when it is desired to reduce the tem erature to which the air is to .be heated wit out reduction of the volume of air delivered.

-For interrupting automatically communication between the fan 5 and the casing when the supply of current to the fan motor is out off and the fan runner is at rest, there is provided a downwardly opening damper or, preferably, two such. dampers 7, hinged at the outer edge and counter-balanced with a bias toward closing so slight as to be overcome by the air pressure set up by the fan 5 when running. When the fan runner is at rest, the dampers 7 swing upwardly on their hinges so that they close the discharge side of the fan and permit the passage of an upward current of warm air which is free to pass through permanent openings 8 in the Walls-of the casing 2 adjacent to the upper end thereof. When the fan is running, the air pressure suffices to move the dampers to open position, so that they are brought into contact with the uppermost radiator sections, in which position the dampers closethe passage to the permanent openings 8 aforesaid and guide the air I into the inner wedge-shaped space 3.

What I claim is v 1. Air heating apparatus, comprising, in combination, a casing formed with inlet and outlet openings, tubular heating elements within said casing, said elements comprising parallelly disposed horizontal sections arranged in inclined banks, converging toward one of said openings, the walls of said casing converging toward theother opening, so as to inclose between said banks an inner wedge-shaped space and to aflord outer wedge-shaped spaces between said banks inlet opening between the sections comprising said banks to said outlet opening.

2. Air heating apparatus, comprising, in combination, a casing having an air inlet and an air outlet, and a lateralopening ad- ]acent to said inlet, tubular heating elements within said casing, a fan for causing a current of air to flow through said casing in contact with said tubular elements, and a damper adapted to cut ofi communication between said fan and said casing but movable by the current of air from said fan to permit communication between said fan and said casing to close said opening.

In testimony whereof I have signed m name to this specification in the presence of two subscribing witnesses.

JAMES MGCORKINDALE ARNEIL. Witnesses:

HENRY MASON, KATHARINE FOTHERINGHAM. 

